The objectives of this project are: (1) To characterize developmental patterns from daily measurements of gonadotropins and for estrogens in premenarchial girls and pubescent boys based on radioimmuno assay methods for measuring urinary luteinizing hormone, urinary follicle stimulating hormone, and urinary estradiol, estriol and estrone hormones, (2) gonadotropins in both castrated and intact male monkeys of different ages, ad (3) growth hormone in normal and precocious pubertal children. (4) To assess circadian and other rhythms in heart rate, temperature and other serial data collected from long-term studies in humans, (5) To perform analysis of these serial measurements using methods of statistical time series analysis, including autoregressive filtering, auto- and cross-spectrum analysis, and robust smoothing procedures.